Everything You Need To Know About Sea Vegetables

In a time when taking care of your health and immune system is more important than ever, there's one superfood you may be neglecting: Sea veggies. Sure, you've eaten those bits of seaweed in your miso soup, or wrapped around your sushi roll.

However, there is actually a wide variety of green, brown, and red seaweed or edible marine algae that fall into the sea vegetables category. And they are bursting with nutrients, some of which you just can't get from land vegetables.  

"Sea vegetables are a great addition to a healthy diet, right now and always," says registered dietitian Abby Cannon, J.D., R.D., CDN. But where do you start when it comes to this variety of veggies? Can you get them in your grocery store, or is there a sea vegetables supplement?

Sea vegetables and their various incarnations go way beyond the dehydrated seaweed snack packs you may find at the grocery store.

The term refers to edible marine algae, which includes some of the most primitive life forms on Earth and can be unicellular (microscopic) or multicellular. Seaweed is a subset of this enormous category of thousands of species. 

Surprisingly, these organisms aren't plants, even though they resemble them. They have no root system because they're able to absorb nutrients and water directly into their tissues. 

Seaweed can be further classified as green, red, or brown. Non-seaweed veggies include single-cell algae like spirulina and chlorella.

There is considerable diversity in the edible seaweed family. The many available varieties come with different nutrition profiles and uses. The red algae—nori—might be the most familiar because it's typically used as sushi wrap or garnish. However, as seaweed becomes more mainstream, seaweed snacks, oils, seasonings, and even jerky are popping up in stores. 

There are nearly 30 varieties of this large brown algae, known colloquially as "seaweed." This is the version of sea vegetable you are most likely to feel clinging to your legs while in the ocean. But you've probably also encountered kelp in your day-to-day while firmly on land; it's found in thousands of products. 

This briny seaweed is often sold in thin, dry sheets, either plain or toasted, and is what you usually find holding your sushi roll together. This is a great seaweed for the pantry because it lasts a very long time and can add instant umami (savoriness due to the amino acid, glutamate) to any dish. 

A type of blue-green algae, spirulina is a single-celled cyanobacteria that has been referred to as the most nutrient-rich food on the planet. Originally used by the Aztecs, it was resurrected by NASA to feed astronauts1 in space. 

Full of the same range of nutrients as other sea vegetables, dulse resembles red, leafy lettuce. But you probably won't find dulse raw. It's usually dried immediately after harvesting and sold as whole-leaf, flakes, powder, or in seasoning mixes. 

A brown seaweed, wakame is another popular one and is traditionally used in cold salads or as a topping on tofu, soup, sushi, or rice. 

When it's cold and dreary outside, break out the kombu and the stockpot. This seaweed is used in dashi, a traditional Japanese stock. Use kombu alone or with dried bonito flakes for miso soup or as a seasoning liquid in other dishes. Better yet, combine with beans or other hard-to-digest vegetables like Brussels sprouts or cabbage. Kombo has enzymes that break down gas-producing raffinose sugars found in many legumes and vegetables. 

Unfortunately, we are regularly exposed to heavy metals from the products we use, pollution in our air, the food we consume (hello, high-mercury tuna), and even the fillings in our teeth. 

Iodine is critical for thyroid health; without enough, you run the risk of hypothyroidism, which can cause a host of issues, including weight gain, fatigue, and goiter. It can cause complications during pregnancy, affect brain and bone development, and even cause pregnancy loss.

Excess free radicals cause cell destruction9, DNA damage, and are thought to contribute to many adverse health conditions. Antioxidants prevent this damage by scavenging free radicals.* The term itself can refer to a wide range of substances, including specific vitamins (A, C, E, and beta-carotene are the most common), flavonoids, and carotenoids, among many others. 

Seaweed gives your gut some love. It's got more fiber than most fruits and vegetables, between 25 and 75% by dry weight12, which helps with digestion and keeps things moving.* And it's full of prebiotics, which feed the good bacteria in your gut and curbs the harmful ones.* It might even protect against H. pylori13, bacteria that can cause stomach ulcers, although these studies have yet to be carried out in humans.* 

In case you weren't paying attention, sea veggies are brimming with vitamins and minerals.* Aside from the antioxidants mentioned above, you'll find iron, copper, manganese, folate, zinc, sodium, calcium, and magnesium. 

These fatty acids get a lot of attention in health news lately, and with good reason—they protect against a range of adverse health conditions, especially benefitting cardiovascular health.* 

We all know that we can find the all-important omega-3s14 in fatty fish, but the fish are getting them from their diet of sea algae10, and you should too! 

So, how do you get your hands on these good-for-you veggies? One of the easiest ways to incorporate sea veggies into your day is to add a powdered form—such as mbg's organic veggies+—to smoothies, a bowl of soup, or simply a glass of water. If you're using a veggie powder, Cannon also suggests using it as a topping for your favorite snacks, like popcorn.

If you're able to find fresh or dried seaweed, experiment with it in dishes, until you learn your preferences. "Try a bunch out and see what you like," advises Cording. For example, if you don't like the strong taste of kombu, often used in soups, then give wakame's milder flavor a try in a seaweed salad. 

Whether you are purchasing fresh, dried, or powdered, it is important to look for certified organic sea vegetables. Sea vegetables are naturally absorbent, so they can pick up contaminants and heavy metals15 from their surroundings.

Organic sea vegetables are grown in controlled aquacultures or wild harvested in protected waters to ensure quality and purity.

"Buy the best quality possible," Frank Lipman, M.D., functional medicine pioneer, advises. "As with land veggies, look for seaweed that’s minimally processed, dried without additives or preservatives, and harvested from clean waters."

According to Cording, you should shoot for at least 4-5 servings per week, although the serving size will depend on the variety and form (fresh, dried, etc.). "That could be a half-cup of cooked seaweed, dried dulse flakes, or a handful of chlorella tablets," she explains.